Phenylpropylammonium salts, as growth regulants

ABSTRACT

Phenylpropylammonium salts of the formula ##STR1## where R 1  denotes for instance alkyl or halogen, R 2  denotes for instance alkyl or alkoxy, R 3  denotes alkyl, alkenyl or alkynyl of up to 6 carbon atoms, R 4  and R 5  denote hydrogen or alkyl of up to 3 carbon atoms, m denotes one of the integers 0, 1, 2 and 3, n denotes one of the integers 0, 1 and 2, o denotes one of the integers 4, 5 and 6, X.sup.θ  denotes an anion, and the dashed bond may be hydrogenated when n is 0 or 1, and is hydrogenated when n is 2; the preparation of these compounds; and agents for regulating plant growth containing these compounds as active ingredients.

This is a division of application Ser. No. 213,789, filed Dec. 8, 1980,now U.S. Pat. No. 4,554,066.

The present invention relates to novel, quaternary phenylpropylammoniumsalts, processes for their manufacture, and agents containing thesecompounds which are suitable for regulating plant growth.

The growth-regulating properties of 2-chloroethyltrimethylammoniumchloride (CCC) (J. Biol. Chem., 235, 475, 1960) in cereals and othercrops have been disclosed (U.S. Pat. No. 3,156,554). Other ammoniumsalts having a growth-regulating action have also been disclosed (GermanLaid-Open Application DE-OS Nos. 2,017,497; 2,114,512; and 2,459,129).

When these prior art agents are used for regulating plant growth, theiraction, particularly at low application rates and concentrations, isoften insufficient.

We have now found novel phenylpropylammonium salts of the formula##STR2## where R¹ denotes alkyl, cycloalkyl, alkoxy, acyl or halogen, R²denotes alkyl, alkenyl or alkoxy, R³ denotes C₁ -C₆ -alkyl, C₃ -C₆-alkenyl or alkynyl, R⁴ and R⁵ denote hydrogen or C₁ -C₃ -alkyl, mdenotes one of the integers 0, 1, 2 and 3, n denotes one of the integers0, 1 and 2, o denotes one of the integers 4, 5 and 6, X.sup.θ denotesthe anion of a non-phytotoxic acid, and the dashed bond may behydrogenated when n is 0 or 1, and is hydrogenated when n is 2. The term"propyl", for the purposes of the invention, thus also embracesmonounsaturated propyl, viz., propenyl. Agents containing these newcompounds as active ingredients have powerful growth-regulatingproperties.

Examples of meanings for R¹ are 2-methyl, 3-methyl, 4-methyl,4-tert-butyl, 3-methyl-4-chloro, 2-methyl-4-chloro, 4-cyclopentyl,4-cyclohexyl, 4-methoxy, 4-acetyl, 4-propionyl, 2-chloro, 4-chloro,2,4-Cl₂, 2,3,4-Cl₃, 2,4,5-Cl₃,4-bromo and 2-fluoro.

Examples of meanings for R² are methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, n-pentyl, prop-1-enyl, but-1-enyl, methoxy andethoxy.

Examples of meanings for R³ are methyl, ethyl, propyl, n-butyl,isobutyl, allyl, crotyl, propynyl and butynyl.

Examples of meanings for R⁴ and R⁵ are hydrogen, methyl, ethyl, n-propyland isopropyl. Taking into account that o is 4, 5, or 6, the radical

    --N(CR.sup.4 R.sup.5).sub.o

is, in the simplest cases (i.e., when R⁴ and R⁵ are hydrogen),pyrrolidine, piperidine or hexamethylenimine. These are preferredbecause of their ease of accessibility. When these heterocycles aresubstituted (R⁴ and/or R⁵ =C₁ -C₃ -alkyl), those are preferred in whichfrom 1 to 3 of the methylene radicals are substituted and bear in eachcase only one substituent. When the methylene radicals aredisubstituted, methyl and ethyl are preferred.

The upper carbon limit for R¹ and R² is not restricted to 5; radicalshaving from 1 to 4 carbon atoms are preferred, but radicals with 6carbon atoms are also suitable.

By "non-phytotoxic anions", we mean those which, at the rates the activeingredient is applied, do not impair its effectiveness and thus presentno phytotoxic hazards. Particularly suitable examples of such anions areiodine, bromine, chlorine, sulfate, tosylate, mesylate,dodecylsulfonate, dodecylphenylsulfonate and 4-bromophenylsulfonate, asthese are usually obtained on manufacture of the compounds. They maythen be replaced in conventional manner, e.g., by the anions nitrate,phosphate, acetate or benzoate. Accordingly, the anions may be mono- orpolyvalent, and organic or inorganic.

The compounds according to the invention may be employed as activeingredients in growth regulators. The agents according to the inventionsurprisingly have a much stronger growth-regulating action on cropplants than the prior art 2-chloroethyl-trimethylammonium chloride,which is accepted as being a good compound having the same kind ofaction.

The starting compounds for the manufacture of the novelphenylpropylammonium salts of the formula I are phenylpropylamines (someof which are disclosed in German Laid-Open Application DE-OS No.2,752,096) of the formula ##STR3## where R¹, R², R⁴, R⁵, m, n and o havethe above meanings. These tertiary amines may be reacted in conventionalmanner with quaternizing agents to give the end compounds. Suitablequaternizing agents in addition to the alkyl, alkenyl and alkynyl (R³)halides are, for example, dimethylsulfate, diethylsulfate and sulfonicacid esters of the formula R--SO₃ R³, R denoting C₁₋₂₀ -alkyl orhalogen- or alkyl-substituted phenyl.

Alternative starting materials are phenylpropyl halides of the formula##STR4## where R¹, R² and m have the above meanings and X denotes Cl, Bror I, some of which are also disclosed in German Laid-Open ApplicationDE-OS No. 2,752,096.

The following scheme shows how compounds II and III may be manufacturedby generally known reactions. The manufacture of the aldehydes IV isdisclosed by B. Zeeh and E. Buschmann in Liebigs Ann. Chem., p. 1585,1979. ##STR5##

It will be clear from this scheme that the novel phenylpropylammoniumsalts are obtained by reacting a phenylpropylamine of the formula IIwith an alkylating agent of the formula R³ X, R³ and X having the abovemeanings. Alternatively, the active ingredients according to theinvention are obtained by reacting a phenylpropyl halide of the formulaIII with tertiary amines of the formula ##STR6## where R³, R⁴, R⁵ and ohave the above meanings.

The reaction of the phenylpropylamines II with R³ X and the reaction ofthe phenylpropyl halides III with the tertiary amines V are carried outfor instance at from 10° to 150° C. in the presence or absence of asolvent, e.g., ethanol, methanol, CHCl₃, CH₂ Cl₂, acetonitrile,dimethylformamide or ethyl acetate, and at atmospheric orsuperatmospheric pressure.

The following examples illustrate the preparation of the compoundsaccording to the invention.

N-Crotonyl-N-[3-(2,4-dichlorophenyl)-2-methyl-2-prop-1-en-1yl-propyl]-pyrrolidiniumbromide (Example 20)

A solution of 31.2 g ofN-[3-(2,4-dichlorophenyl)-2-methyl-2-prop-1-en-1-yl-propyl]-pyrrolidineand 27 g of crotyl bromide in 250 ml of ethyl acetate is refluxed for 5hours. The mixture is then stirred for 15 hours at room temperature andthe crystalline product which is obtained is filtered off, washed withether and dried in vacuo. 15 g of the desired product is obtained; m.p.:128° C.

N-(3-(2,4-Dichlorophenyl)-2-methyl-propyl)-N-methyl-hexamethyleneimmonium bromide (Example 29)

19 g of methyl bromide is gassed into 300 ml of acetonitrile. After theaddition of 30 g ofN-[3-(2,4-dichlorophenyl)-2-methylpropyl]-hexamethylenimine, the mixtureis stirred at room temperature for 15 hours and then concentrated. Theresidue crystallizes upon trituration with ethyl acetate. The crudeproduct is filtered off, washed with ethyl acetate and dried in vacuo.There is obtained 18 g ofN-[3-(2,4-dichlorophenyl)-2-methyl-propyl]-N-methyl-hexamethyleneimmonium bromide; m.p.: 178° C.

N-Allyl-N-[2-methyl-3-(o-methyl-phenyl)-propyl]-pyrrolidinium bromide(Example 24)

A solution of 51 g ofN-[2-methyl-3-(o-methyl-phenyl)-propyl]-pyrrolidine and 58 g of allylbromide in 200 ml of ethyl acetate is refluxed for 5 hours. The productprecipitates as a resin. After the ethyl acetate has been decanted, thecrude product is triturated several times with ethyl acetate.Supernatant solvent is decanted. Finally, the product is triturated withn-pentane and the solvent decanted. The oil which remains is freed fromsolvent residues in a rotary evaporator. There remains 60 g ofN-allyl-N-[2-methyl-3-(o-methyl-phenyl)-propyl]-pyrrolidinium bromide asa brown resin.

The following compounds are obtainable in the same way:

                                      TABLE 1                                     __________________________________________________________________________     ##STR7##                                                                     Example No.                                                                          (R.sup.1).sub.m                                                                     R.sup.2   R.sup.3                                                                            (CR.sup.4 R.sup.5).sub.o                                                                 X m.p.                                 __________________________________________________________________________     1     4-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                      2     2,4-Cl                                                                              CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              110°                           3     2,4-Cl                                                                              C.sub.2 H.sub.5                                                                         Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                      4     2,4-Cl                                                                              n-C.sub.4 H.sub.9                                                                       Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                      5     2,4-Cl                                                                              n-C.sub.5 H.sub.11                                                                      Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              109°                           6     H     H         Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                      7     H     CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                      8     2,4-Cl                                                                              Isopropyl Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                               75°                           9     2,3,4-Cl                                                                            n-C.sub.4 H.sub.9                                                                       Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                     10     2,4-Cl                                                                              OCH.sub.3 Allyl                                                                              (CH.sub.2 ).sub.4                                                                        Br                                     10 A   2,4-Cl                                                                              n-C.sub.5 H.sub.11                                                                      Allyl                                                                              (CH.sub.2).sub.5                                                                         Br                                                                              148°                          __________________________________________________________________________     ##STR8##                                                                     Example No.                                                                          (R.sup.1).sub.m                                                                     (R.sup.2).sub.n                                                                         R.sup.3                                                                            (CR.sup.4 R.sup.5).sub.o                                                                 X m.p.                                 __________________________________________________________________________    11     2-F   CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                12     4-Acetyl                                                                            CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                13     2,4-Cl                                                                              CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                14     2,4-Cl                                                                              CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Cl                                     15     4-Br  H         Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              127-8°                        16     4-OCH.sub.3                                                                         CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                17     2,4,5-Cl                                                                            H         Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              112-115°                      18     2,4-Cl                                                                              iso-Propyl                                                                              Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              123°                          19     2,4-Cl                                                                              n-Propyl  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                20     2,4-Cl                                                                              Methyl Propen-1-yl                                                                      Crotyl                                                                             (CH.sub.2).sub.4                                                                         Br                                                                              128°                          21     3-CH.sub.3,4-Cl                                                                     CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                22     4-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              147°                                       Propen-1-yl                                                      23     2,4-Cl                                                                              (CH.sub.3).sub.2                                                                        Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              136-8°                        24     2-CH.sub.3                                                                          CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                25     3-CH.sub.3                                                                          CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                     __________________________________________________________________________    Example No.                                                                          (R.sup.1).sub.n                                                                     (R.sup.2).sub.n                                                                         R.sup.3                                                                            (CR.sup.4 R.sup.5).sub.o                                                                 X M.p.                                 __________________________________________________________________________    26     2-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              105°                          27     2,4-Cl                                                                              Methyl Propen-1-yl                                                                      Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              172-4°                        28     2,4-Cl                                                                              CH.sub.3  Ethyl                                                                              (CH.sub.2).sub.6                                                                         Br                                                                              176-8°                        29     2,4-Cl                                                                              CH.sub.3  Methyl                                                                             (CH.sub.2).sub.6                                                                         Br                                                                              178°                          30     2,4-Cl                                                                              CH.sub.3  Allyl                                                                              (CH.sub.2).sub.6                                                                         Br                                                                              177-180°                      31     4-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.6                                                                         Br                                                                               76-77°                       32     4-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.5                                                                         Br                                                                               55-58°                       33     4-t-Butyl                                                                           CH.sub.3  Allyl                                                                              (CH.sub. 2).sub.4                                                                        Br                                                                              125°                          34     2,4-Cl                                                                              CH.sub.3  CH.sub.3                                                                           (CH.sub.2).sub.4                                                                         Br                                                                              resin                                35     H     CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                36     4-Cl  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                37     2,3,4-Cl                                                                            CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                     38     2,3,4-Cl                                                                            n-C.sub.4 H.sub.9                                                                       Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                39     2,3,4-Cl                                                                            Isopropyl Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                     40     2,4,5-Cl                                                                            H         Crotyl                                                                             (CH.sub.2).sub.4                                                                         Br                                                                              resin                                41     2,4-Cl                                                                              CH.sub.3  Crotyl                                                                             (CH.sub.2).sub.4                                                                         Br                                                                              resin                                42     2,4-Cl                                                                              n-Propyl  Allyl                                                                              (CH.sub.2).sub.4                                                                         I                                      43     2,4-Cl                                                                              OCH.sub.3 Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                44     2,4-Cl                                                                              CH.sub.3  Allyl                                                                              (CH.sub.2).sub.3CHCH.sub.3 CH.sub.2                                                      Br                                     45     2,4-Cl                                                                              n-C.sub.3 H.sub.7                                                                       Propynyl                                                                           (CH.sub.2).sub.4                                                                         Br                                     46     4-Br  CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                47     4-CH.sub.3                                                                          CH.sub.3  Allyl                                                                              (CH.sub.2).sub.4                                                                         Br                                                                              resin                                48     2,4-Cl                                                                              n-C.sub.3 H.sub.7                                                                       Allyl                                                                              (CH.sub.2).sub.5                                                                         Br                                                                              resin                                __________________________________________________________________________

Plant growth regulators may have several different effects on plants.The action of the compounds depends essentially on the time applied,with reference to the development stage of the seed or plant, on theamount of active ingredient applied to the plants of their habitat, andon the application method employed. At all events, growth regulators areintended to influence crop plants in a desired manner.

Plant growth-regulating compounds may be used for instance to inhibitvegetative plant growth. Such a reduction in growth is of economicinterest inter alia in grass, because as a result of depressed grassgrowth it is possible for instance to reduce the frequency of mowing inornamental gardens, parks, sportsgrounds and on roadsides. It isimportant to inhibit the growth of herbaceous and woody plants onroadsides and in the vicinity of overhead transmission lines, or quitegenerally where vigorous growth is undesired.

A further important application area for growth regulators is theinhibition of upward plant growth in cereals (which include rice). Areduction in stem length reduces or completely eliminates the danger oflodging before the plants are harvested. Growth regulators may alsostrengthen the stem of cereals, which also counteracts lodging.

The inhibition of vegetative growth also makes closer planting possiblein numerous crops, which means an increase in yield based on the areacropped.

A further mechanism for increasing yields with plant growth regulatorsis based on the fact that blossom and fruit formation benefits to agreater extent from the nutrients when vegetative growth is restricted.

However, plant growth regulators may also frequently be employed topromote vegetative growth. This is of great use when the vegetativeplant parts are harvested. The promotion of vegetative growth may,however, simultaneously result in an increase in generative growth,e.g., the formation of more or bigger fruit.

Increases in yield may also be achieved in many instances by influencingplant metabolism without there being any noticeable change in vegetativegrowth. Growth regulators may also change the composition of plants andthus improve the quality of the harvested products. It is for examplepossible to increase the sugar content of sugar beets, sugarcane,pineapples and citruses, or to raise the protein content in soybeans andcereals.

Parthenocarpic fruits may also be formed under the influence of growthregulators. Further, the sex of the flowers may be influenced.

The production or the flow of secondary plant materials may also bepositively influenced with growth regulators. The stimulation of latexflow in rubber trees may be mentioned by way of example.

During the growth of the plant, branching may be increased by growthregulators as a result of the chemical control of apical dominance. Thisis of interest for instance in the propagation of plant cuttings. It is,however, also possible to inhibit the growth of lateral branches, e.g.,to prevent sucker growth in tobacco plants after topping, and thus topromote leaf growth.

Growth regulators may also be used to defoliate plants at any desiredtime. Such a defoliation facilitates mechanical harvesting, e.g., ingrapes or cotton, or reduces transpiration at a time when the plant isto be transplanted.

Premature fruit drop may also be prevented by growth regulators. It is,however, also possible to thin out chemically by promoting fruit drop toa certain extent. Growth regulators may also be used to reduce the forceto be exerted for plucking off fruit from crop plants at harvest time,making mechanical harvesting possible, or facilitating manualharvesting.

Further, growth regulators may be used to accelerate or delay theripening of material before or after harvesting. This feature is ofparticular advantage, because market needs can be optimallyaccommodated. Growth regulators may also in many cases improve fruitcolor. It is also possible to concentrate ripening with growthregulators, thus making it possible, for example in tobacco, tomatoes orcoffee, to harvest completely mechanically or manually in just oneoperation.

Growth regulators can also influence the dormancy of seeds or bids,i.e., the annual endogenous rhythm; plants such as pineapples orornamentals in nurseries can thus be made to germinate, sprout orblossom at a time at which they normally show no willingness to do so.

Growth regulators may further be employed to delay budding or seedgermination, for example in order in frost-endangered areas to preventdamage by late frosts.

Growth regulators may also make crop plants halophilic, i.e., they maybe cultivated in salty soils.

Growth regulators can also make plants more frost- anddrought-resistant.

In view of the different crops in which growth regulators can be used,the various action targets, and differing soil and weather conditions,it will be clear that it is not possible to state the requisiteapplication rates for every individual case. However, the skilled workerwill have no difficulty in ascertaining the most suitable applicationrates because the largest useful amount is generally 5 kg of activeingredient per hectare. In soybeans, for instance, approx. 0.25 toapprox. 2.5 kg/ha may be applied postemergence.

The agents are applied for instance in the form of directly sprayablesolutions, powders, suspensions (including high-percentage aqueous, oilyor other suspensions), dispersions, emulsions, oil dispersions, pastes,dusts, broadcasting agents, or granules by spraying, atomizing, dusting,broadcasting or watering. The forms of application depend entirely onthe purpose for which the agents are being used; in any case they shouldensure as fine a distribution of the active ingredient as possible.

For the preparation of solutions, emulsions, pastes and oil dispersionsto be sprayed direct, mineral oil fractions of medium to high boilingpoint, such as kerosene or diesel oil, further coal-tar oils, and oilsof vegetable or animal origin, aliphatic, cyclic and aromatichydrocarbons such as benzene, toluene, xylene, paraffin,tetrahydronaphthalene, alkylated naphthalenes and their derivatives suchas methanol, ethanol, propanol, butanol, chloroform, carbontetrachloride, cyclohexanol, cyclohexanone, chlorobenzene, isophorone,etc., and strongly polar solvents such as dimethylformamide,dimethylsulfoxide, N-methylpyrrolidone, water, etc. are suitable.

As the active ingredients according to the invention are salts, aqueousformulations are preferred. They may be prepared from emulsionconcentrates, pastes, oil dispersions or wettable powders by addingwater. To prepare emulsions, pastes and oil dispersions the ingredientsas such or dissolved in an oil or solvent may be homogenized in water bymeans of wetting or dispersing agents, adherents or emulsifiers.Concentrates which are suitable for dilution with water may be preparedfrom active ingredient, wetting agent, adherent, emulsifying ordispersing agent and possibly solvent or oil.

Examples of surfactants are: alkali metal, alkaline earth metal andammonium salts of ligninsulfonic acid, naphthalenesulfonic acids,phenolsulfonic acids, alkylaryl sulfonates, alkyl sulfates, and alkylsulfonates, alkali metal and alkaline earth metal salts ofdibutylnaphthalenesulfonic acid, lauryl ether sulfate, fatty alcoholsulfates, alkali metal and alkaline earth metal salts of fatty acids,salts of sulfated hexadecanols, heptadecanols, and octadecanols, saltsof sulfated fatty alcohol glycol ethers, condensation products ofsulfonated naphthalene and naphthalene derivatives with formaldehyde,condensation products of naphthalene or naphthalenesulfonic acids withphenol and formaldehyde, polyoxyethylene octylphenol ethers, ethoxylatedisooctylphenol, ethoxylated octylphenol and ethoxylated nonylphenol,alkylphenol polyglycol ethers, tributylphenyl polyglycol ethers,alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcoholethylene oxide condensates, ethoxylated castor oil, polyoxyethylenealkyl ethers, ethoxylated polyoxypropylene, lauryl alcohol polyglycolether acetal, sorbitol esters, lignin, sulfite waste liquors and methylcellulose.

Powders, dusts and broadcasting agents may be prepared by mixing orgrinding the active ingredients with a solid carrier.

Granules e.g., coated, impregnated or homogeneous granules, may beprepared by bonding the active ingredients to solid carriers. Examplesof solid carriers are mineral earths such as silicic acid, silica gels,silicates, talc, kaolin, Attaclay, limestone, lime, chalk, bole, loess,clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate,magnesium oxide, ground plastics, fertilizers such as ammonium sulfate,ammonium phosphate, ammonium nitrate, and ureas, and vegetable productssuch as grain flours, bark meal, wood meal, and nutshell meal,cellulosic powders, etc.

The agents according to the invention may additionally contain otheractive ingredients, e.g., herbicides and/or fungicides.

The results of biological tests with the agents according to theinvention evidence a most remarkable growth-regulating action, as thefigures given in the tables below show. To determine thegrowth-regulating properties of the active ingredients, soil providedwith sufficient nutrients was filled into plastic pots about 12.5 cm indiameter and test plants were grown therein. The compounds to be testedwere sprayed as a postemergence treatment onto the plants as aqueousformulations. The growth-regulating action observed was confirmed at theend of the experiment by height measurements. The values obtained werecompared with those for untreated plants. The prior art compound CCC wasused for comparison purposes.

Not only was growth height reduced--the leaves also took on a moreintense color. The increased chlorophyll content is indicative of ahigher rate of photosynthesis, making for bigger yields. ##STR9##

                  TABLE 2                                                         ______________________________________                                        Soybeans                                                                      Postemergence treatment                                                                 mg of active ingredient                                                                       Growth height                                       Ex. no.   per vessel      %                                                   ______________________________________                                        untreated --              100                                                 CCC       1.5             96.5                                                          6.0             88.8                                                19        1.5             50.0                                                          6.0             39.3                                                13        1.5             61.8                                                          6.0             45.9                                                34        1.5             67.7                                                          6.0             51.8                                                41        1.5             65.7                                                          6.0             51.8                                                28        1.5             58.4                                                          6.0             52.0                                                43        1.5             48.7                                                          6.0             42.2                                                35        1.5             60.1                                                          6.0             55.1                                                ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        Sunflowers                                                                    Postemergence treatment                                                                 mg of active ingredient                                                                       Growth height                                       Ex. no.   per vessel      %                                                   ______________________________________                                        untreated --              100                                                 CCC       1.5             89.5                                                          6.0             81.7                                                19        1.5             70.3                                                          6.0             58.6                                                17        1.5             66.2                                                          6.0             61.3                                                13        1.5             69.0                                                          6.0             61.3                                                34        1.5             70.0                                                          6.0             64.2                                                46        1.5             75.1                                                          6.0             61.4                                                43        1.5             75.1                                                          6.0             61.4                                                ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        Sunflowers                                                                    Postemergence treatment                                                                   mg of active ingredient                                                                       Growth height                                     Ex. no.     per vessel      %                                                 ______________________________________                                        untreated                                                                            --       --              100                                           CCC    --       1.5             93.8                                                          6               85.9                                                  8       1.5             89.3                                                          6               71.4                                                 21       1.5             62.3                                                          6               56.8                                                 24       1.5             80.1                                                          6               70.3                                                 47       1.5             63.4                                                          6               56.0                                                 26       1.5             70.9                                                          6               57.8                                          ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Soybeans                                                                      Postemergence treatment                                                                   mg of active ingredient                                                                       Growth height                                     Ex. no.     per vessel      %                                                 ______________________________________                                        untreated                                                                            --       --              100                                           CCC    --       0.5             97.1                                                          1.5             97.1                                                 21       0.5             80.2                                                          1.5             73.8                                                 24       0.5             78.1                                                          1.5             69.6                                          ______________________________________                                    

We claim:
 1. A method of regulating the upward growth of vegetableplants which comprises: applying to said plants a composition comprisingan aqueous or solid carrier that is compatible with the growthregulating activity of the active agent and an effective amount of aphenylpropyl ammonium salt of the formula ##STR10## where R¹ denotesalkyl of 1 to 6 carbon atoms, cyclopentyl, cyclohexyl, alkoxy of 1 to 6carbon atoms, acetyl, propionyl or halogen, R² denotes alkyl of 1 to 6carbon atoms, alkenyl of up to 6 carbon atoms or alkoxy of 1 to 6 carbonatoms, m denotes one of the integers 0, 1, 2 and 3, and n denotes one ofthe integers 1 and 2 and the dashed bond may be hydrogenated when n is1, and is hydrogenated when n is
 2. 2. A method as defined in claim 1,wherein the phenylpropyl ammonium salt is selected from the groupconsisting of N-allyl-N-[3-(2-fluorophenyl)-2methylpropyl]-pyrrolidiniumbromide, N-ally-N-[3-(2,4-dichlorophenyl)-2-methylpropyl]-pyrrolidiniumbromide,N-allyl-N-[3-(2,4-dichlorophenyl)-2-isopropyl-propyl]-pyrrolidiniumbromide, N-allyl-N-[3-(2,4-dichlorophenyl)-2-propylpropyl]-pyrrolidiniumbromide, N-allyl-N-[2-methyl-3-(o-methylphenyl)-propyl]-pyrrolidiniumbromide and N-allyl-N-[3-(4-chlorophenyl)-2-methylpropyl]-pyrrolidiniumbromide.
 3. A method as defined in claim 1, wherein the phenylpropylammonium salt isN-allyl-L-[2-methyl-3-(o-methyl-phenyl)-propyl]-propylpyrrolidiniumbromide.